Every computer has an interface between its executable routines and a user of the computer. User interfaces may include fields for the computer to output information to the user, and fields by which the user can input information to the computer. Fields may be associated with attributes that define properties of the fields. Changing a field attribute may change how the field is displayed on a screen of the computer.
An example of an existing user interface is the SAP graphical user interface, or “SAPGUI”, provided with SAP systems and servers sold under the name R/3. The SAPGUI uses SAP's “dynamic program” or “dynpro” technology for generating displays in the user interface. The SAPGUI has associated with it flow logic that determines its interaction with the backend. The SAPGUI has a relatively strong relation to a backend of the system.
Other user interfaces, in contrast, may be less strongly tied to the backend. Some web-based server systems are capable of using commercially available web browsers as the user interface. For example, SAP has developed a Web Application Server that uses so called Web Dynpro user interfaces in which the application logic is separated from the user interface.